Bill Carlson of Minnetonka will spend Veterans Day much as he always does. The 62-year-old Vietnam veteran, whose father served under Gen. Patton in WWII, will participate with the Elk River Honor Guard at graveside ceremonies. But unlike any year before, he said, "I'll be thinking of him."

Carlson was given new life with a heart transplant in 2009 at the University of Minnesota Medical Center. He dreamed of learning who the donor was and one day thanking the donor's family in person.

He wrote letters and cards, following protocol by sending them through LifeSource, the region's nonprofit organ and tissue donation agency (www.donatelifemn.org). Staff members forwarded them using only his first name.

Last January, a year and a half after his transplant, Carlson's mailbox finally held the answer. "Dear Bill," the letter began, "I would like to thank you for the cards you sent." It was written by the donor's mother.

Carlson's heart, he learned, came from a 25-year-old soldier with the Minnesota National Guard who served one tour in Iraq. He was 25 when he died, leaving behind a 2-month-old son.

"I cried for three days," Carlson said. "I cry when I read it today." He carries the letter in his wallet.

Carlson grew up in northeast Minneapolis and attended Minneapolis Vocational High School. He was drafted in 1967. "We had lots of friends coming home dead," he said. "We knew we were next in line."

An only child, he spent four years on an attack carrier, making one trip home to marry Naomi, his wife of 40 years. They have three grown daughters and three grandchildren.

After the war, Carlson worked in a cabinet shop. In 1997 the two-pack-a-day smoker was diagnosed with congestive heart failure. He had a pacemaker inserted, then an internal defibrillator device. After one cardiologist suggested hospice care, Naomi sought a second opinion at the U. Doctors there discovered a failing valve in his left ventricle caused by a potentially fatal infection called endocardisis.

During his 5 1/2 months in the hospital, his weight dropped to 118 pounds. A heart pump was implanted as a bridge until a heart transplant match could be found. "I never lost the will to live," Carlson said. He quit smoking, ate "all the red meat I could get my hands on" and regained strength using a treadmill.

The call came on June 7, 2009. A heart was found, and it looked like a perfect match.

Carlson woke up as the U's 683rd heart transplant patient, immediately feeling better. He did outpatient rehab for three months and now gets checkups twice annually. "I'm as healthy as I was 30 years ago," Carlson said, "but the body is still 62."

Eager to give back, he sits on the board of Second Chance For Life, cheering on cardiac patients at the U. He volunteers at LifeSource and speaks to students in health classes and driver's education about the importance of organ donation.

"I lose a lot of friends because there aren't enough hearts available," he said. One died last week at age 42. He pulls out a photo of a 22-year-old woman, also waiting.

"He was one who never liked hospitals and doctors and now he spends so much time there of his own free will," Naomi said. "It's something he feels he needs to do."

In October 2009, Carlson wrote his first letter. "It was, maybe, one page, just saying who I was, how old I was, what I did for a living. I couldn't even say my name." He tried to put words to how grateful he was.

"You can't say, 'Gee, thanks for the heart.' I think I used the words 'wonderful gift.' And that's what it is."

Letter-writing between donors and recipients is a delicate process, said LifeSource spokeswoman Susan Mau Larson. Aside from privacy rules, "our biggest concern is that one of the parties might not be ready." Sometimes, though, the letter is a godsend. "[Donor families] get so much strength from hearing from the recipient," she said.

Since September 2010, more than 600 letters from recipients have come through their offices, which serve Minnesota, the Dakotas and western Wisconsin. Donor families also write or call. "They'll say, 'We just want to know how our loved one's recipient is doing.' They're thinking about that legacy.

"For Bill," Larson said, "writing to his donor's family around Veterans Day was very meaningful for him and for the donor's family."

With her letter, the donor's mother also sent Carlson a picture of her smiling son, an avid outdoorsman, holding a stringer of northerns. "My son had a good heart in every sense," she wrote. "I hope it serves you long and well."

Two weeks ago, Carlson sent her a small American flag to place at her son's graveside. Across it, he lay three ribbons of embroidered satin: